Optical disc recording/reproducing method, optical disc and optical disc device

ABSTRACT

Data recording/reproduction is carried out in a disc format such that error correction codes interleaved with respect to the direction of data on a disc are collectively blocked into an error correction unit and that the input/output order of user data in an ECC block as an error correction unit is made coincident with the direction of processing of the error correction codes. Thus, coding can be started at the time when necessary data for generating one code is transmitted, without waiting for transmission of data for one ECC block. Also, transmission of user data can be started at the time when correction of one code is completed, without waiting for completion of correction operation for one ECC block. Also, since the direction of correction codes is the same as the direction of user data, no memory for rearrangement of data is required and the hardware structure can be minimized. Moreover, since less data transmission/reception takes place between the buffer memory and the external device, bus arbitration can be easily carried out.

TECHNICAL FIELD

[0001] This invention related to an optical disc recording/reproducingmethod, an optical disc and an optical disc device.

BACKGROUND ART

[0002] Conventionally, optical recording media such as a disc-shapedoptical recording medium and a card-shaped optical recording mediumusing an optical or magneto-optical signal recording/reproducing methodhave been developed and provided on the market. As such opticalrecording media, there have been known read-only memory type recordingmedia such as a so-called compact disc (CD), so-called write-once typerecording media which enable data writing once on the user side, andrewritable recording media which enable so-called overwrite such as amagneto-optical (MO) disc.

[0003] In an optical disc device for carrying out writing/reading ofdata onto/from a disc-shaped recording medium, a laser diode foremitting a light beam for information recording/reproduction and aphotodetector for detecting a reflected light of a light beam radiatedonto an optical disc are provided. Using an optical head on whichfocusing servo and tracking servo are performed on the basis of thedetection output from the photodetector, speed servo is performed on aspindle motor and the optical disc is rotated at a constant angularvelocity or a constant linear velocity while a recording track of theoptical disc is scanned with a light beam, thereby carrying out datarecording/reproduction.

[0004] In a magneto-optical disc system prescribed by the InternationalOrganization for Standardization (ISO), blocked codes are employed.

[0005] In the format of magneto-optical disc prescribed by the ISO, thedirection of user data is equal to the direction of data on the disc asshown in FIG. 1. In an ECC block using blocked codes, the direction ofcorrection codes is interleaved with respect to the direction of data onthe disc in order to improve the capability of correcting burst errors.Also, in this format, data immediately after frame synchronization FSbelong to separate identical correction codes, and the second data fromframe synchronization FS belong to separate identical error correctioncodes. Similarly, data immediately before frame synchronization FSbelong to separate identical error correction codes.

[0006] At the time of recording on the optical disc of such a format,when all the user data sent from the application side for one ECC blockis written into a buffer memory 302 through an arbiter 301, as shown inFIG. 2A, an ECC processing section 303 starts error correction coding.After coding of all the data in one ECC block is completed, the codeddata is sent from the buffer memory 302 to modulation means and channelencoding is started. Thus, channel-encoded data is recorded in the userdata area on the disc.

[0007] At the time of reproduction, reproduction data obtained from thedisc is channel-decoded by demodulation means. When all the data for oneECC block is written into the buffer memory 302 through the arbiter 301,as shown in FIG.2B, the ECC processing section 303 starts decoding.After decoding of all the data in one ECC block is completed, the userdata is taken out from the buffer memory 302 and is sent to theapplication side.

[0008] As described above, in the magneto-optical disc system prescribedby the ISO, the direction of user data is equal to the direction of dataon the disc, and the direction of error correction codes is interleavedwith respect to the direction of data on the disc. Therefore, at thetime of recording, error correction coding cannot be started unless allthe user data for one block is written into the buffer memory. Unlesscoding of all the data in the block is completed, channel encoding ofcoded data cannot be started and hence channel-encoded data cannot berecorded onto the disc. At the time of reproduction, decoding cannot bestarted unless reproduction and channel decoding of all the reproductiondata for one block are completed. Unless decoding of all the data in theblock is completed, the user data cannot be taken out from the buffermemory. Thus, the latency time therefor is a fixed delay at the time ofrecording/reproduction. As the ECC block size increases, the fixed delayincreases in proportion to the block size.

[0009] In the case where special recording/reproduction is carried outsuch as after-recording for reproducing, processing and then recordingdata during a short period of time by effectively utilizing the randomaccessibility as a feature of the optical disc, it is desired that thefixed delay at the time of recording/reproduction is as short aspossible.

[0010] In the case of special recording/reproduction such asafter-recording, it is necessary to have a buffer memory correspondingto the time required for data processing between reproduction operationand recording operation and for access on the disc, in order to carryout continuous reproduction operation at a high speed, data processingand then continuous recording operation for securing a transfer rate.Also, not only a transfer rate which is approximately twice higher isrequired for carrying out reproduction and recording operation, but alsothe transfer rate needs to be higher for the time required for dataprocessing and for access on the disc.

[0011] In the case of after-recording, it is considered that data may berecorded at a position on the disc from where it is reproduced. In thecase of continuous reproduction and recording, too, the recordingposition is close to the reproduction position. Therefore, only a shortaccess time is required and the data processing time may beproblematical. In general, a frame synchronizing signal FS is providedat the header part of a frame. If bit slip is generated,re-synchronization can be carried out by using the frame synchronizingsignal FS. If bit slip is generated at a halfway point of a frame, thetiming is shifted in the portion following that point and demodulationcannot be carried out accurately, or the position of demodulated data isshifted. As a result, a data error is generated. After that, when aframe synchronizing signal FS is detected at the header part of the nextframe, the correct timing is obtained and the data is accuratelyreproduced. That is, the data immediately after the frame synchronizingsignal FS is more resistant to an error caused by bit slip, incomparison with the data immediately before the frame synchronizingsignal FS.

[0012] Meanwhile, there has been recently a remarkable increase in thecapacity of the ROM (read only memory) disc and the RAM (random accessmemory) disc using optical recording. Shortening of the wavelength of asemiconductor laser used for the optical head of the optical discrecording/reproducing device and increase in the numerical aperture (NA)of an objective lens for condensing a light beam onto the informationrecording surface of the optical disc are realized.

[0013] Reduction in the spot size is known as a technique for realizinga high-density phase-change type optical disc having a capacity greaterthan that of a DVD-RAM. The spot size on the recording medium issubstantially provided by λ/NA, and can be reduced by a technique usinga short-wavelength semiconductor laser light source made of GaN or ZnSeor a technique of increasing the NA of the objective lens by a two-grouplens represented by a solid immersion lens (SIL).

[0014] For example, on the assumption of λ=640 nm and NA=0.85, thediameter of the spot is approximately 0.75 μm on the medium. If signalsare recorded/reproduced by using RLL(1, 7) modulation, a linearrecording density of approximately 0.21 μm/bit can be realized.

[0015] As typical modulation codes of a modulation system having a broaddetection window of the channel suitable for high-densityrecording/reproduction, an RLL(1, 7) code and an (2, 7) code are known.RLL(1, 7) modulation is a type of modulation with a run length limited(RLL) code having a maximum inversion interval of waveform string, inwhich the minimum run of information (symbol) 0 is 1 and the maximum runis 7. In RLL(1, 7) modulation when converting data having a basic datalength of m bits to a variable-length code (d, k; m, n; r), for example,data having a basic data length m equal to 2 bits is converted to avariable-length code (1, 7; 2, 3; 2) having a minimum run d of 0 equalto 1 bit, a maximum run k of 0 equal to 7 bits, a basic data length mequal to 2 bits, a basic code length n equal to 3 bits and a maximumconstraint length r equal to 2 bits, by using a conversion tableincluding a code for restraining continuation of the minimum length d of0 of the channel bit string of the RLL(1, 7) code for a predeterminednumber of times. For this RLL( 1, 7) modulation, the followingconversion table is used. RLL(1, 7; 2, 3; 2) Data Code i = 1 11 00x 10010 01 10x i = 2 0011 000 00x 0010 000 010 0001 100 00x 0000 100 001

[0016] In this RLL(1, 7) modulation, if the bit interval of therecording waveform string is T, the minimum inversion interval Tmin isequal to 2T. If the bit interval of the data string is Tdata, Theminimum inversion interval Tmin is equal to 1.33(=(m/n)×Tmin =(⅔)×2)Tdata. The maximum inversion interval Tmax is equal to8(=7+1)T(=(m/n)×Tdata=(⅔)×8Tdata=5.33Tdata. The detection window Tw isequal to 0.67(=⅔) Tdata On the other hand, in RLL(2, 7) modulation, whenconverting data having a basic data length of m bits to avariable-length code (d, k; m, n; r), for example, data having a basicdata length m equal to 2 bits is converted to a variable-length code (2,7; 1, 3; 2 ) having a minimum run d of 0 equal to 2 bits, a maximum runk of 0 equal to 7 bits, a basic data length m equal to 1 bit, a basiccode length n equal to 3 bits and a maximum constraint length r equal to2 bits, by using a conversion table including a code for restrainingcontinuation of the minimum length d of 0 of the channel bit string ofthe RLL(2, 7) code for a predetermined number of times. For this RLL(2,7) modulation, the following conversion table is used. RLL(2, 7; 1, 3;2) Data Code i = 1 11 10 00 10 01 00 i = 2 011 00 10 00 010 10 01 00 00000 01 00 i = 3 0011 00 00 1000 0010 00 10 0100

[0017] In this RLL(2, 7) modulation, if the bit interval of therecording waveform string is T, the minimum inversion interval Tmin(=(d+1)T) is equal to 3T. If the bit interval of the data string isTdata, the minimum inversion interval Tmin is equal to1.5(=(m/n)×Tmin×(⅔)×3) Tdata. The maximum inversion interval Tmax(=(k+1)T) is equal to 8(=7+1)T(=(m/n)×Tmax)Tdata=(½)×8Tdata=4.0Tdata.The detection window Tw (=(m/n)×T) is equal to 0.5(=½)Tdata. In theoptical disc system using an optical head having a high-NA objectivelens, it is necessary to enhance the error correction capability inorder to cope with errors due to the influence of dust particles orscratches on the optical disc surface onto the light beam. To enhancethe error correction capability, codes are increased or the ECC block isincreased. Moreover, there is proposed a method of interleaving andcollectively blocking the error correction codes in order to broaden theECC block to the size equivalent to one track on the inner circumferenceof the disc.

[0018] If blocked codes are used, a block size of not smaller than 64 KBcan be constituted as user data even when general GF(2⁸) is used ascodes. In addition, the present Assignee has proposed, in the JapanesePublication of Unexamined Patent Application No. Hei 9-285899, anoptical disc recording/reproducing method, an optical disc and anoptical disc device in which address information is provided as a partof data within a frame so that a common data format is used for both aread-only disc and a recordable disc. According to this technique, in ablock format determined as shown in FIG. 3, the code length of the ECCblock is 196 (172 information words and 24 parity words), the interleavelength is 384, the number of sectors in this block is 16, the number offrames per sector is 49, the number of data within a frame is 96, andthe user data per sector is equivalent to 4 KB. The data of 24 byteswithin the leading frame of each sector is address information. Thedirection of data on the disc corresponds to frames 0, 1, 2 , . . . ,783 (blocks=total sectors).

[0019] In the block format shown in FIG. 3, the interleave length islong in comparison with the frame length, and the header data of eachframe is not on the same code but is concentrated at one of the fourcodes.

[0020] Thus, it is an object of the present invention to provide anoptical disc recording/reproducing method, an optical disc and anoptical disc device for recording/reproduction of data in a disc formatsuch that the fixed delay at the time of recording/reproduction can bereduced.

[0021] It is another object of the present invention to provide anoptical disc recording/reproducing method, an optical disc and anoptical disc device for recording/reproduction of data in a disc formatsuch that correction incapability caused by concentration of data of aspecified position within a frame to a specified code can be avoided.

[0022] In the case of reproduction, the correction capability withrespect to a product code (PRC) can be improved by strategy. However,this can be realized on the assumption that correction processing iscarried out for a plurality of times.

[0023] On the other hand, in the ECC block formed by interleaving andcollectively blocking error correction codes so as to broaden the ECCblock to the size corresponding to one track on the inner circumferenceof the disc for improving the error correction capability, the codestructure is in one direction and therefore the number of times ofcorrection is basically one.

[0024] At the time of recording, too, the product code must be encodedin two directions, that is, parity generation must be carried out.However, if blocked codes are used, encoding is carried out only in onedirection.

[0025] Thus, if the block size of the ECC block is the same, the fixeddelay at the time of recording/reproduction is smaller for the ECC blockusing blocked codes which require a smaller number of times ofcorrection, than in the case where the product code is used.

[0026] Moreover, the fixed delay at the time of recording/reproductioncan be significantly reduced by causing the direction of user data(input/output order) to be equal to the direction of correction codes asshown in FIG. 4. In the case of FIG. 4, the direction of correctioncodes and the direction of user data are made coincident with eachother, using the same capacity as that of the magneto-optical discprescribed by the ISO.

[0027] In the optical disc system having such a disc format that thedirection of correction codes and the direction of user data are madecoincident with each other, in reproduction, correction operation forreproduction data is carried out from when transmission of data for oneECC block from the demodulator is completed. This is because thedirection of correction codes is interleaved with respect to thedirection of data on the disc. Then, the user data can be transmitted tothe buffer memory from when correction of one code is completed. Thatis, it is not necessary to wait for correction operation for one ECCblock. This is because the direction of correction codes and thedirection of user data are made equal to each other.

[0028] Similarly, in recording, coding can be started at the time whennecessary data for generating one code is transmitted, without waitingfor user data for one ECC block from the buffer memory. After that, whencoding of one ECC block is completed, the data is transmitted to themodulator and recorded onto the disc.

[0029] The operation timing in this optical disc system is shown in FIG.5, in comparison with the above-described case of the magneto-opticaldisc system. As shown in FIG. 5, the fixed delay at the time ofrecording/reproduction can be reduced by the amount of “margin” inreproduction and recording. Also, a margin can be provided for dataprocessing in reproduction and recording. Alternatively, the total dataprocessing time and therefore the buffer memory can be reduced. Inaddition, since the direction of correction codes is the same as thedirection of user data, no memory for data rearrangement is required andthe hardware structure can be minimized. Also, since less datatransmission/reception takes place between the buffer memory and theexternal device, bus arbitration can be easily carried out.

[0030] Moreover, higher resistance to errors can be obtained bydispersing words within the same code to a broad range of words withinthe frame.

Disclosure of the Invention

[0031] According to the present invention, data recording/reproductionis carried out, for example, in a format such that interleave processingis performed on error correction codes so as to collectively block theerror correction codes into an error correction unit and that theinput/output order of user data in an ECC block as an error correctionunit is made coincident with the direction of processing of the errorcorrection codes.

[0032] Also, according to the present invention, datarecording/reproduction is carried out, for example, in a disc formatsuch that the ECC block is constituted by one or more sectors, thesector is constituted by a plurality of frames, the block length of theECC block is expressed by the following equation,

block length=number of sectors×number of frames×frame length=codelength×interleave length

[0033] the number of sub-sectors is expressed by the following equation,

number of sub-sectors=number of sectors×p

[0034] (where p=number of segments: natural number) and {codelength×interleave length}/{segment length×number of sub-sectors} %number of sub-sectors (where % indicates modulo) and the number ofsub-sectors are prime numbers, respectively.

[0035] Also, according to the present invention, datarecording/reproduction is carried out, for example, in a disc formatsuch that the ECC block is constituted by one or more sectors, thesector is constituted by a plurality of frames, the block length of theECC block is expressed by the following equation,

block length=number of sectors×number of frames×frame length=codelength×interleave length

[0036] the number of sub-sectors is expressed by the following equation,

number of sub-sectors=number of sectors×p

[0037] (where p=number of segments: natural number)

[0038] and when the code length is divisible by q (where q=number ofsubblocks: natural number), {{code length/q}×interleave length}/{segmentlength×number of sub-sectors} % number of sub-sectors (where % indicatesmodulo) and the number of sub-sectors are prime numbers, respectively.

[0039] Moreover, according to the present invention, datarecording/reproduction is carried out, for example, in a disc formatsuch that the number of data within the segment is smaller than thenumber of data within the frame and that the correction code position isupdated for each segment while the interleave rule is met in causing thedata position on the disc to correspond to the data position on the ECCblock.

[0040] Also, according to the present invention, datarecording/reproduction is carried out, for example, in a disc formatsuch that the correction code position is updated by one byte.

[0041] Also, in the optical disc recording/reproducing method and theoptical disc device according to the present invention, datarecording/reproduction is carried out, for example, in a disc formatsuch that the ECC block is constituted by one or more sectors, thesector is constituted by a plurality of frames, the block length of theECC block is expressed by the following equation,

block length=number of sectors×number of frames×frame length=codelength×interleave length

[0042] and a sector ID is provided holding the following relations.

[0043] sector ID length×number of sectors interleave length×k

[0044] (where k is a natural number)

[0045] sector ID length=segment length×p

[0046] (where p=number of segments: natural number)

[0047] Also, in the optical disc recording/reproducing method and theoptical disc device according to the present invention, datarecording/reproduction is carried out, for example, in a disc formatsuch that {code length×interleave length}/{segment length×number ofsectors} % number of sectors (where % indicates modulo) and the numberof sectors are prime numbers, respectively.

[0048] In addition, according to the present invention, datarecording/reproduction is carried out, for example, in a disc formatsuch that the number of sectors is 2^(n) and that {codelength×interleave length}/{sector ID length×number of sectors} is an oddnumber.

[0049] Also, in the optical disc recording/reproducing method and theoptical disc device according to the present invention, datarecording/reproduction is carried out, for example, in a disc formatsuch that the number of data within the segment is smaller than thenumber of data within the frame and that the correction code position isupdated for each segment while the interleave rule is met in causing thedata position on the disc to correspond to the data position on the ECCblock.

[0050] Moreover, according to the present invention, datarecording/reproduction is carried out, for example, in a plurality ofdisc formats having different ECC block sizes in accordance with thesetting of the number of sectors and interleave length.

BRIEF DESCRIPTION OF THE DRAWINGS

[0051]FIG. 1 schematically shows the frame structure within an ECC blockin the format of a magneto-optical disc prescribed by the ISO.

[0052]FIGS. 2 and 2B schematically show the flow of data inrecording/reproduction operation with respect to the magneto-opticaldisc prescribed by the ISO.

[0053]FIG. 3 schematically shows an exemplary frame structure within anECC block in a disc format previously proposed by the present Assignee.

[0054]FIG. 4 schematically shows the structure of an ECC block in whichthe direction of user data is the same as the direction of correctioncodes.

[0055]FIG. 5 shows the operation timing in an optical disc system,comparing a conventional ECC block in which the direction of user datais different from the direction of correction codes and an ECC block inwhich the direction of user data is the same as the direction ofcorrection codes.

[0056]FIG. 6 schematically shows the structure of an ECC block in anoptical disc system according to the present invention.

[0057]FIGS. 7A and 7B schematically show the structure of frames withinthe ECC block shown in FIG. 6.

[0058]FIG. 8 schematically shows the data configuration within a sectorin the optical disc system employing the ECC block.

[0059]FIG. 9 schematically shows the relation between the dataconfiguration within the sector and ECC (information words and parity).

[0060]FIG. 10 schematically shows the frame structure within the ECCblock.

[0061]FIG. 11 schematically shows the arrangement and structure of dataunits within the ECC block.

[0062]FIG. 12 schematically shows user data in the optical disc system.

[0063]FIG. 13 schematically shows the frame structure within the ECCblock in the case where one ECC block is constituted by one sector.

[0064]FIGS. 14A and 14B schematically show another frame structurewithin the ECC block.

[0065]FIG. 15 schematically shows the data configuration within thesector in the case of the frame structure shown in FIGS. 14A and 14B.

[0066]FIG. 16 schematically shows the relation between the dataconfiguration within the sector and ECC (information words and parity)in the case of the frame structure shown in FIGS. 14A and 14B.

[0067]FIG. 17 schematically shows the arrangement and structure of dataunits within the ECC block in the case of the frame structure shown inFIGS. 14A and 14B.

[0068]FIG. 18 is a block diagram showing the structure of a disc driveof an optical disc recording/reproducing device for carrying outrecording/reproduction of user data onto/from an optical disc accordingto the present invention.

[0069]FIG. 19 is a schematic cross-sectional view showing the structureof an aspherical two-group objective lens unit provided in an opticalhead of the disc drive.

[0070]FIG. 20 is a block diagram showing a recording/reproductionprocessing unit in the optical disc recording/reproducing device.

[0071]FIGS. 21A and 21B schematically show the flow of data inrecording/reproduction operation carried out by the optical discrecording/reproducing device.

[0072]FIG. 22 schematically shows another structure of the ECC block inthe optical disc system according to the present invention.

[0073]FIG. 23 schematically shows the frame structure within the ECCblock shown in FIG. 22.

[0074]FIG. 24 schematically shows the arrangement and structure of dataunits within the ECC block shown in FIG. 22.

[0075]FIG. 25 schematically shows another structure of the ECC block inthe optical disc system according to the present invention.

[0076]FIGS. 26A and 26B schematically show the frame structure in theECC block shown in FIG. 25.

[0077]FIG. 27 schematically shows the data configuration within thesector in the optical disc system employing the ECC block shown in FIG.25.

[0078]FIG. 28 schematically shows the frame structure within the ECCblock shown in FIG. 25.

[0079]FIG. 29 schematically shows the arrangement and structure of dataunits within the ECC block shown in FIG. 25.

[0080]FIGS. 30A and 30B schematically show another structure of the ECCblock in the optical disc system according to the present invention.

[0081]FIGS. 31A and 31B schematically show the frame structure in theECC block shown in FIG. 30B.

[0082]FIG. 32 schematically shows the data configuration within thesector in the optical disc system employing the ECC block shown in FIG.30B.

[0083]FIG. 33 schematically shows the frame structure within the ECCblock shown in FIG. 30B.

[0084]FIG. 34 schematically shows the arrangement and structure of dataunits within the ECC block shown in FIG. 30B.

BEST MODE FOR CARRYING OUT THE INVENTION

[0085] Preferred embodiments of the present invention will now bedescribed in detail with reference to the drawings.

[0086] In an optical disc system according to the present invention, anECC block having a block format as shown in FIG. 6 is employed.

[0087] The ECC block shown in FIG. 6 is constituted by binding codes of206 information words and 29 parity words for 320 lines. Therefore, theECC block has a code length of 235 (206 information words and 29 paritywords) and an interleave length of 320. If each code of 235 words withrespect to each “g” is expressed by D(i, j) (where i=0 to 234, j=32 0 to319) as shown in FIG. 6, the code is generated to satisfy the followingEquation 1. $\begin{matrix}{{\sum\limits_{i = 1}^{234}{D_{i} \cdot x^{({234 - i})}}} = {{p_{D}(x)} \cdot {g_{D}(x)}}} & \text{(Equation~~1)}\end{matrix}$

[0088] In this Equation 1, g(x) is a generating polynomial and isexpressed by g(x)=(x−α²⁸)·(x−α²⁷) . . . (x−α²), where α is the root ofthe original polynomial f(x)=x⁸+x⁴+x³+x²+x⁰ on GF(2⁸).

[0089] With respect to the data of the ECC block, the number of data ofone frame is 100 bytes as shown in the frame structure of FIG. 7A. Whenthis data is (1, 7)-modulated, the number of data equal to 100 bytes perframe is changed to 1200 channels as shown in FIG. 7B. In the framestructures shown in FIGS.7A and 7B, B(s, t, u, v) is modulated to m(s,t, u, w), where “s” represents the sector, “t” represents the frame, “u”represents the segment, “v” represents the data (bytes), and “w”represents the channel after modulation. In addition, a DCC channel orthe like for appending a DCC code to the control of DC components in the(1, 7) modulation system by each DC control cell (DCC) may be provided.

[0090] A segment is equivalent to 20 bytes, which is equal to the sectorID length. Since a segment has 20 bytes equivalent to the sector IDlength, the number of segments within a frame is 5.

[0091] The number of sectors in this ECC block is 16 and the number offrames per sector is 47. The user data per sector is equivalent to 4 KB.

[0092]FIG. 8 shows the configuration of recording/reproduction data onthe disc. As shown in FIG. 8, a frame sync part FS is appended to theheader of a channel string on the frame (channel) basis. Also, APC andVFO parts are appended to the header of every 47 frames (channels) and apostamble PO is appended to the last part, thus constituting one sector.In this case, APC is a light-emitting pattern area for controlling therecording laser power at the time of recording. VFO is a pattern areafor applying PLL for clock extraction at the time of reproduction. Asthe frame sync part FS, a unique pattern for realizing channelsynchronization, which does not appear in the modulation rule, is used.In this embodiment, the frame sync FS0 indicating the header of thesector is discriminated from the other frame sync parts FS1. However, asector sync part SS may be inserted between VFO and FS.

[0093] The relation between the data configuration within the sector andECC (information words and parity) is shown in FIG. 9, and the framestructure within the ECC block is shown in FIG. 10.

[0094] In this embodiment, the number of sectors is 16=2⁴, and k=1holds. Therefore, in causing the data position on the disc to correspondto the data position on the ECC block on the assumption that the codelength is an odd number while the number of data within the segment issmaller than the number of data within the frame, a disc format is usedsuch that the correction code position is updated for each segment whilethe interleave rule is met. Thus, the one-to-one correspondence betweenthe data on the disc and the data on the ECC block can be realized.

[0095] In the ECC block shown in FIG. 6, the direction of data on thedisc is provided by the rising order of B(s, t, u, v), that is, by thearrangement numbers from the upper position to the lower position in theorder of s, t, u and v. The relation between D(i, j) and B(s, t, u, v)is expressed by the following equation.

B(s, t, u, v)=D(i,j)=D([(((47×s)+t)×20+v)/20]%235,((((47×s)+t)×5+u)×20+v)/20%320)

[0096] In this equation, [r] is the maximum positive integer notexceeding r, and % indicates modulo. This is similarly applied in thefollowing description.

[0097] The leading segment of the leading frame of each sectorrepresents the sector ID.

[0098] In this embodiment, since the segment has 20 bytes, the number ofsectors is 16, the interleave length is 320, and k=1 holds, thefollowing relation is obtained.

segment length×number of sectors=interleave length×k

[0099] (where k=1)

[0100] That is, 20×16=320×1 is obtained. In the above-describedarrangement, the sector ID corresponds to the first one word ofinformation words of all the correction codes, and the user datacorresponds to the second and subsequent words of information words ofall the correction codes. Therefore, the direction of user data can bemade equal to the direction of correction codes without being disturbedby the header.

[0101] The arrangement of data units within the ECC block is shown inFIG. 11, and the structure of data units is shown in FIG. 12. H(g, h) isheader information, that is, sector ID information. U(g, h) is userdata. E(g, h) is an error detection code (EDC) of the user data. “g” isthe number of data units, and “h” is the number of data.

[0102] The direction of EDC (direction of error detection) may also bethe same as the direction of ECC codes. Error detection with EDC isperformed on the entire data of the data unit, that is, the user dataand EDC.

[0103] EDC is generated to satisfy the following Equation 2, forexample. $\begin{matrix}{{{\sum\limits_{h = 0}^{4095}{U_{h} \cdot x^{({4099 - h})}}} + {\sum\limits_{h = 0}^{3}{E_{h} \cdot x^{({4099 - 4096 - h})}}}} = {{p_{E}(x)} \cdot {g_{E}(x)}}} & \text{(Equation~~2)}\end{matrix}$

[0104] In this Equation 2, g(x) is a generating polynomial and isexpressed by g(x)=(x−α³)·(x−α²)·(x−α¹)·(x−⁰), where α is the root of theoriginal polynomial f(x)=x⁸+x⁴+x³+x²+x⁰ on GF(2⁸).

[0105] The header information H(g, h) includes information which is usedas ID by, for example, the CPU of the control section, and a part ofthis information might be used as physical address information such asthe sector. In addition, the header information may include informationsuch as the preface of the disc. Moreover, the error detection code maybe appended to this information. The sector ID may include an area fordummy data or the like which is replaced by a synchronization pattern.This has no meaning to the application side and the CPU of the controlsection.

[0106] The user data U(g, h) and the result of detection using the errordetection code E(g, h) are also used by the CPU of the control section.However, only the user data U(g, h) must be transmitted to theapplication side.

[0107] The arrangement in which the direction of the user data U(g, h)is made equal to the direction of the error detection codes E(g, h) isexpressed by the following relational expressions between D(i, j) andU(g, h), E(g, h).

U(g, h)=D(i, j)=D((h×205)+1, 20×g+[h/205])

[0108] where h is 0to 4095 and g is 0to 15

E(g, h)=D(i, j)=D(((4096+h)%205)+1, 20 ×g+[(4096+h)/205])

[0109] where h is 0 to 3 and g is 0 to 15

[0110] As for the header information H(g, h), the following relationexpression is obtained.

H(g, h)=D(i, j)=D(0, 20×g+h)

[0111] where h is 0 to 19 and g is 0 to 15

[0112] In reproduction, by carrying out EDC check after correction for anecessary quantity, the user data can be immediately sent to theapplication side. That is, it suffices only to wait for completion ofthe correction operation for the data unit and it is not necessary towait for the correction operation for one block. Moreover, after the endof the correction operation of the data unit, it is possible to send theuser data to the application side as soon as the required correctionoperation of codes is completed without waiting for completion of EDCcheck, then carry out EDC check at the last part of the data unit andsend the result to the CPU.

[0113] In recording, error correction codes can be generated while theuser data is sent from the application side. At the time whentransmission of information words of one code is completed, parity wordscorresponding to the code can be generated.

[0114] The error detection codes EDC, too, can be generated at the timewhen the user data for one data unit is sent.

[0115] Thus, by carrying out the EDC generation operation simultaneouslywith transmission of the user data, then carrying out arithmeticoperation with respect to the transmitted information words in the userdata portion of each error correction code, and carrying out arithmeticoperation with respect to the generated parity in the parity wordportion, the error detection codes EDC can be generated.

[0116] By using the above-described disc format, the header data (B(x,x, 00)) of the leading segment of each frame is dispersed by the numberof sectors at every segment length, and is dispersed to 16 codes forevery 20 lines within the interleave length, as shown in FIG. 11.Therefore, correction incapability due to concentration of data of aspecified position within a frame to a specified code can be avoided,and higher resistance to errors generated by bit slip can be obtained.

[0117] When the number of sectors is to be reduced in order to reduceredundancy such as a pre-header, the above-described sectors may begathered into an actual sector.

[0118] In the case where the data is used for purposes other than AV,for example, for a computer storage, it may be desired to reduce thefile size. In the computer storage, a defective area is avoided bysubstitution. Therefore, in some cases, there may be employed a formatfor reducing the ECC block even though the error correction capabilityis lowered. Further, there is also an advantage such that discs of twosimilar formats can be handled in a common device. For example, thoughone ECC block is constituted by 16 sectors in the above-describedembodiment, an independent ECC block for each sector enablesrecording/reproduction with discs of the same physical format.

[0119] The frame structure within the ECC block in the case where oneECC block is constituted by one sector is shown in FIG. 13.

[0120] In the frame structure shown in FIG. 13, data of one sectorconstitutes one ECC block, and user data of one ECC block constitutesone data unit. In this case, too, the direction of data within the dataunit may be the same as the direction of ECC.

[0121] The frame structure within the ECC block in the case where thestructure of the ECC block is the same as that of FIG. 6 while thenumber of sectors is 32 is shown in FIGS. 14A and 14B.

[0122] In this frame structure, the number of data within a frame is 50bytes, as shown in FIG. 14A, and 50 bytes per frame is (1, 7)-modulatedto 600 channels, as shown in FIG. 14B. That is, a segment has 10 bytes(120 channels) and a frame has 5 segments =50 bytes (600 channels).Address information is included in one segment.

[0123] The structure in which the number of sectors within the ECC blockis 32 is shown in FIG. 15. The frame structure within the ECC block isshown in FIG. 16.

[0124] The arrangement of data units within the ECC block is shown inFIG. 17. As shown in FIG. 17, the number of data units within the ECCblock is 16.

[0125] In the case where ID information of the data unit is to be sentto the CPU, the address information of sector 0 is expressed by H(0, 0to 9) and the address information of sector 1 is expressed by H(0, 10 to19). Then, H(0, 0 to 19) or information necessary for ID obtainedtherefrom is used as ID information of the data unit 0.

[0126] As the number of sectors is thus increased, the segment becomessmaller. Therefore, in comparison with the case of the disc format shownin FIGS 6 to 12, correction incapability due to concentration of data ofa specified position within a frame to a specified code can be avoidedfurther, and higher resistance to errors generated by bit slip can beobtained.

[0127] Next, for recording/reproduction of user data onto/from anoptical disc of such a format, an optical disc recording/reproducingdevice having the following structure is used, for example.

[0128] This optical disc recording/reproducing device has a disc drive100 of a structure as shown in FIG. 18, in which an optical disc 101 isrotationally driven at a constant angular velocity by a spindle motor102 while the information recording surface of the optical disc 101 isscanned with a laser beam by an optical head 110, thus opticallyrecording/reproducing information.

[0129] The optical head 110 provided in the disc drive 100 has asemiconductor laser (LD) 103 as a light source for radiating a laserbeam for recording/reproduction to the optical disc 101 . The lightemitted from the semiconductor laser 103 is collimated by a collimatinglens 104 and passes through a diffraction grating 105 for size spotgeneration. After that, the light becomes incident on an asphericaltwo-group objective lens unit 120 through a beam splitter 106 and aquarter-wave plate 107, and is condensed onto the information recordingsurface of the optical disc 101 by the aspherical two-group objectivelens unit 120. A part of the light emitted from the semiconductor laser103 is reflected by the beam splitter 106, then led to an emission powermonitor detector 109 through a condenser lens 108, and used forautomatic power control for controlling the laser power on theinformation recording surface. A reflected light (that is, areproduction signal) from the optical disc 101 is reflected by the beamsplitter 106 and then led to a detection optical path. A part of thislight is reflected by a beam splitter 111, then made incident on a servosignal detector 114 through a condenser lens 112 and a cylindrical lens113, and then photoelectrically converted. The remaining part of thelight is made incident on an RF signal detector 117 through lenses 115,116 and then photoelectrically converted. In this optical head 110, afocusing error signal is generated by using an astigmatic method, and atracking error signal is generated by using a differential push-pullmethod. In this case, a servo error signal and a reproduction RF signalare detected by the two signal detectors 114, 117. However, only onedetector may suffice.

[0130] The aspherical two-group objective lens unit 120 has a firstelectromagnetic actuator 122 for driving a first lens 121, and a secondelectromagnetic actuator 124 for driving a second lens 123, as shown inFIG. 19. The second lens 123 is mounted on the second electromagneticactuator 124 movable in the direction of optical axis and in thedirection of tracks, and has a numerical aperture of approximately 0.5.The first lens 121 is mounted on the first electromagnetic actuator 122different from the second electromagnetic actuator 124, above the secondlens 123, and is controllable at an arbitrary position on the opticalaxis.

[0131] This optical disc recording/reproducing device has arecording/reproduction processing block 200 having a structure as shownin FIG. 20 and connected to the disc drive 100 for carrying outrecording/reproduction by scanning the information recording surface ofthe optical disc 100 by the optical head 110.

[0132] This recording/reproduction processing block 200 has a computeror central processing unit (CPU) 202 and an arbitration processingsection 203 for carrying out transmission/reception of user data andcontrol data to/from the application side through an application I/Fcircuit 201. A buffer memory 204 and an ECC processing section 205 areconnected to the arbitration processing section 203. Also, an in-sectortiming generator 206 and a reproduction timing generator 207 areconnected to the arbitration processing section 203.

[0133] The recording/reproduction processing block 200 also has amodulation section 208 to which recording data is supplied from thearbitration processing section 203 at the time of recording, and apattern generation section 211 and a selector section 212 which operatein accordance with a timing signal provided by the in-sector timinggenerator 206. The modulation section 208 performs modulation processingconformable to the RLL(1, 7) modulation rule on the recording datasupplied from the arbitration processing section 203, and supplies themodulation output to the selector section 212. The pattern generationsection 211 generates APC, VFO and PO patterns. The selector section 212selects the outputs of the modulation section 208 and the patterngeneration section 211 in accordance with a timing signal provided bythe in-sector timing generator 206, thus generating and supplying arecording channel signal to the disc drive 100.

[0134] The in-sector timing generator 206 carries out RLL(2, 7)demodulation on a reproduction signal of an address area (sector IDarea) AR2 of the optical disc 101 supplied from the disc drive 100 so asto obtain address information, and supplies the address information assector position information to the CPU 202. Also, the in-sector timinggenerator 206 generates each timing signal within the sector on thebasis of the sector position information, and controls the operation ofthe modulation section 208, the pattern generation section 21 1 and theselector section 212 at the time of recording. At the time ofreproduction, the in-sector timing generator 206 supplies a referencetiming signal to the reproduction timing generator 207. The CPU 202carries out access control for recording/reproducing the user data onthe basis of the control data provided from the application side and thesector position information provided by the in-sector timing generator206.

[0135] Moreover, the recording/reproduction processing block 200 has asynchronization detection section 213 and a demodulation section 214, toboth of which a reproduction channel signal is supplied from the discdrive 100 at the time of reproduction. The synchronization detectionsection 213 detects a synchronizing signal included in the reproductionchannel signal and supplies the detected synchronizing signal to thereproduction timing generator 207. Then, the demodulation section 214carries out RLL(1, 7) demodulation processing, on the reproductionchannel signal, corresponding to RLL(1, 7) modulation processing in themodulation section 208 on the basis of a timing signal provided by thereproduction timing generator 207 so as to generate reproduction data,and supplies the reproduction data to the arbitration processing section203.

[0136] In the recording/reproduction processing block 200 of such astructure, in recording, user data is sent from the application side tothe ECC processing section 205 and ID information and reserved data aresent from the CPU 202, as shown in FIG. 21A. Then, IDE generation andEDC generation are carried out by the ECC processing section 205 and ECCencoding is carried out. Thus, data within the ECC block is prepared onthe buffer memory 204.

[0137] The ECC processing section 205 starts coding at the time whennecessary data for generating one code is supplied, without waiting forarrival of user data for one ECC block onto the buffer memory 204.

[0138] After that, when coding for one ECC block is completed, the datawithin the ECC block prepared on the buffer memory 204 is RLL(1,7)-modulated by the modulation section 208 at the timing of the sectorto be recorded, indicated by a timing signal from the in-sector timinggenerator 206. The modulated data is sent to the disc drive 100 throughthe selector section 212, as a recording channel signal to which theAPC, VFO, SS and PO patterns generated by the pattern generation section211 are appended. The recording channel signal is then recorded into theuser area of the optical disc 101.

[0139] In this case, in the arbitration processing section 203,rearrangement of the respective data is carried out by arbitratingaddress signals for the buffer memory generated from each block.

[0140] On the other hand, in reproduction, a synchronizing signal isdetected from a reproduced reproduction channel signal by thesynchronization detection section 213 and is supplied to thereproduction timing generator 207, thus performing synchronizationprotection. Then, RLL(1, 7) demodulation is carried out by thedemodulation section 214 on the basis of the timing and reproductiondata is sent to the buffer memory 204, as shown in FIG. 21B. Then, ECCdecoding is carried out by the ECC processing section 205 and EDC checkand IDE check are carried out. In the ECC processing section 205,correction operation for the reproduction data is started at the timewhen transmission of data for one ECC block from the demodulationsection 214 is completed, and transmission of the user data is startedat the time when correction of one code is completed. That is, it is notnecessary to wait for the correction operation for one ECC block.

[0141] In the above-described embodiments, the code position (word) isupdated on the segment basis corresponding to the length of header, thatis, sector ID. However, in realizing correspondence of the data positionon the disc to the data position on the ECC block on the assumption thatthe number of data within the segment is smaller than the number of datawithin the frame, the correction code position may be updated for eachsegment while the interleave rule is met, and datarecording/reproduction may be carried out in a disc format such that theECC block is constituted by one or more sectors, the sector isconstituted by a plurality of frames, the block length of the ECC blockis expressed by the following equation,

block length=number of sectors×number of frames×frame length=codelength×interleave length

[0142] the number of sub-sectors is expressed by the following equation,

number of sub-sectors=number of sectors×p

[0143] (where p=number of segments: natural number) and {codelength×interleave length}/{segment length×number of sub-sectors} %number of sub-sectors (where % indicates modulo) and the number ofsub-sectors are prime numbers, respectively.

[0144] For example, with respect to an ECC block in which the codelength obtained by binding and blocking codes of 207 information wordsand 28 parity words for 320 lines is 235 (207 information words and 28parity words) and in which the interleave length is 320, as shown inFIG. 22, the data has the frame structure shown in FIG. 7 and has thedata configuration within the segment shown in FIG. 8, similarly to theECC block having a code length of 235 (206 information words and 29parity words) and an interleave length of 320 shown in FIG. 6.

[0145] That is, the ECC block shown in FIG. 6 is the same as an ECCblock having the following structure.

[0146] number of sectors=16, number of frames=47, frame length=100 bytes

[0147] code length=235, interleave length=320

[0148] sector ID=20, k=1

[0149] segment length=20, p=1, number of sub-sectors=16

[0150] As for the ECC block shown in FIG. 22, the user data within theECC block is 64 KB and the number of constituent sectors is 16.

[0151] The frame structure within the ECC block of this case is shown inFIG. 23, and the arrangement and structure of data units are shown inFIG. 24. H(g, h) represents header information, that is, sector IDinformation. R(g, h) represents 20-byte information at the leading partof each data unit. U(g, h) represents user data. E(g, h) represents anerror detection code (EDC) of the user data. “g” is the number of dataunits, and “h” is the number of data.

[0152] In the ECC block shown in FIG. 22, the direction of data on thedisc is provided by the rising order of B(s, t, u, v), that is, by thearrangement numbers from the upper position to the lower position in theorder of s, t, u and v. The relation between D(i, j) and B(s, t, u, v)is expressed by the following equation.

B(s, t, u, v)=D(i, j)=D([((((47×s)+t)×5+u)×20+v)/20]%235,((((47×s)+t)×5+u)×20+v)/20%320)

[0153] The arrangement in which the direction of the user data U(g, h)is made equal to the direction of the error detection codes E(g, h) isexpressed by the following relational expressions between D(i, j) andR(g, h), U(g, h), E(g, h).

R(g, h)=D(i, j)=D((h%206)+1, 20×g+[h/206])=D(h+1, 20×g)

[0154] where h is 0 to 19 and g is 0 to 15

U(g, h)=D(i, j)=D(((20+h)%206)+1, 20 33 g+[(20+h)/206])

[0155] where h is 0 to 4095 and g is 0 to 15

E(g, h)=D(i, j)=D(((4116+h)%206)+1, 20×g+[(4116+h)/206])

[0156] where h is 0 to 3 and g is 0 to 15

[0157] As for the header information H(g, h), the following relationexpression is obtained.

H(g, h)=D(i, j)=D(0, 20×g+h)

[0158] where h is 0 to 19 and g is 0 to 15

[0159] Thus, in the ECC block shown in FIG. 22, specified data withinthe frame, for example, the leading data of the frame are dispersed to16 positions at every 20 codes. The sector ID has 20 bytes at theleading part of each sector.

[0160] The ECC block shown in FIG. 13 in which one ECC block isconstituted by one sector is the same as an ECC block having thefollowing structure.

[0161] number of sectors=1, number of frames=47, frame length=100 bytes

[0162] code length=235, interleave length=20

[0163] sector·ID=20, k=1

[0164] segment length=20, p=1, number of sub-sectors=1

[0165] In this ECC block, the user data within the ECC block has 4 KBand the number of constituent sectors is 1. The leading data of theframe are dispersed to one position at every 20 codes. The sector ID has20 bytes at the leading part of each sector.

[0166] Further, the ECC block of the format shown in FIGS 14 to 17 isthe same as an ECC block having the following structure.

[0167] number of sectors=32, number of frames=47, frame length=50 bytes

[0168] code length=235, interleave length=320

[0169] sector ID=10, k=1

[0170] segment length=10, p=1, number of sub-sectors=32

[0171] In this ECC block, the user data within the ECC block has 64 KBand the number of constituent sectors is 32. The leading data of theframe are dispersed to 32 positions at every 10 codes. The sector ID has10 bytes at the leading part of each sector.

[0172] In the ECC block shown in FIG. 22, the user data within the ECCblock has 64 KB and the number of constituent sectors is 16, similarlyto the ECC block shown in FIG. 6. Thus, the sector ID is concentrated.However, in an ECC block having a structure such that

[0173] number of sectors=16, number of frames=100, frame length=47 bytes

[0174] code length=235, interleave length=320

[0175] sector ID=20, k=1

[0176] segment length=5, p=4, number of sub-sectors=64,

[0177] the number of user data within the ECC block is 64 KB and thenumber of constituent sectors is 16. The leading data of the frame aredispersed to 64 positions at every five codes. Thus, the sector ID isdispersed to four positions for every five bytes.

[0178] Moreover, in an ECC block having a structure such that

[0179] number of sectors=16, number of frames=50, frame length=94 bytes

[0180] code length=235, interleave length=320

[0181] sector ID=20, k=1

[0182] segment length=10, p=2, number of sub-sectors=32,

[0183] the number of user data within the ECC block is 64 KB and thenumber of constituent sectors is 16. The leading data of the frame aredispersed to 32 positions at every 10 codes. Thus, the sector ID isdispersed to two positions for every 10 bytes.

[0184] By thus dispersing specified words within the frame, that is,sector ID, higher resistance to errors can be obtained.

[0185] In addition, in realizing correspondence of the data position onthe disc to the data position on the ECC block on the assumption thatthe number of data within the segment is smaller than the number of datawithin the frame, specified words within the frame may be dispersed to abroad range by updating the correction code position for each byte whilemeeting the interleave rule.

[0186] For example, in an ECC block in which the code length obtained bybinding and blocking codes of 207 information words and 30 parity wordsfor 320 lines is 237 (207 information words and 30 parity words) and inwhich the interleave length is 320, as shown in FIG. 25, the number ofdata of one frame of the ECC block is 79 bytes as shown in the framestructure of FIG. 26A, and is modulated to 948 channels by (1, 7)modulation as shown in FIG. 26B.

[0187] In the frame structure shown in FIGS 26A and 26B, B(s, t, u, v)is modulated to im(s, t, u, w), where “s” represents the sector, “t”represents the frame, “u” represents the segment, “v” represents thedata (bytes), and “w” represents the channel after modulation. Inaddition, a DCC channel or the like for appending a DCC code to thecontrol of DC components in the (1, 7) modulation system by each DCcontrol cell (DCC) may be provided.

[0188] The configuration of recording/reproduction data on the disc isshown in FIG. 27. As shown in FIG. 27, a frame sync part FS is appendedto the header of a channel string on the frame (channel) basis. Also,APC and VFO parts are appended to the header of every 60 frames(channels) and a postamble PO is appended to the last part, thusconstituting one sector. In this case, APC is a light-emitting patternarea for controlling the recording laser power at the time of recording.VFO is a pattern area for applying PLL for clock extraction at the timeof reproduction. As the frame sync part FS, a unique pattern forrealizing channel synchronization, which does not appear in themodulation rule, is used. In this embodiment, as the frame sync FS, theframe sync FS0 indicating the header of the sector is discriminated fromthe other frame sync parts FS1. However, a sector sync part SS may beinserted between VFO and FS.

[0189] In this ECC block, the following structure is employed.

[0190] number of sectors=16, number of frames=60, frame length 79 bytes

[0191] code length=237, interleave length=320

[0192] sector ID=20, k 1

[0193] segment length=1, p=20, number of sub-sectors=320

[0194] Thus, in realizing correspondence of the data position on thedisc to the data position on the ECC block, the correction code positionis updated for each segment, that is, for each byte while the interleaverule is met. By doing so, the one-to-one correspondence between the dataon the disc and the data on the ECC block can be realized.

[0195] The frame structure within the ECC block is shown in FIG. 28.

[0196] In the ECC block shown in FIG. 25, the direction of data on thedisc is provided by the rising order of B(s, t, u, v), that is, by thearrangement numbers from the upper position to the lower position in theorder of s, t, u and v. The relation between D(i, j) and B(s, t, u, v)is expressed by the following equation.

B(s, t, u, v)=D(i, j)=D([((((60×s)+t)×79+u)×1+v)/1]%237,((((60×s)+t)+t)×79+u)×1+v)%320)

[0197] By this arrangement, the one-to-one correspondence between thedata of one block on the disc and the entire data on the ECC block canbe realized while the interleave rule is met. In this case, the header,that is, sector ID corresponds to the first one word of informationwords of all the correction codes, and the user data corresponds to thesecond and subsequent words of information words of all the correctioncodes. Therefore, the direction of user data can be made equal to thedirection of correction codes without being disturbed by the header.

[0198] The arrangement of data units within the ECC block and thestructure of data units are shown in FIG. 29. H(g, h) is headerinformation, that is, sector ID information. R(g, h) is 20-byteinformation at the leading part of each data unit. U(g, h) is user data.E(g, h) is an error detection code (EDC) of the user data. “g” is thenumber of data units, and “h” is the number of data.

[0199] The arrangement in which the direction of the user data U(g, h)is made equal to the direction of the error detection codes E(g, h) isexpressed by the following relational expressions between D(i, j) andR(g, h), U(g, h), E(g, h).

R(g, h)=D(i, j)=D((h%206)+1, 20×g+[h/206])=D(h+1, 20×g)

[0200] where h is 0 to 19 and g is 0 to 15

U(g, h)=D(i, j)=D(((20+h)%206)+1, 20×g+[(20+h)/206])

[0201] where h is 0 to 4095 and g is 0 to 15

E(g, h)=D(i, j)=D(((4116+h)%206)+1, 20×g+[(4116+h)/206])

[0202] where his 0 to 3 and g is 0 to 15

[0203] As for the header information H(g, h), the following relationexpression is obtained.

H(g, h)=D(i, j)=D(0, (((20×g+h)/1)×237+((20×g+h)%1))%320)=D(0,((20×g+h)×237%320))

[0204] where his 0 to 19 and g is 0 to 15

[0205] Thus, in the ECC block shown in FIG. 25, the number of user datawithin the ECC block is 64 KB and the number of constituent sectors is16. The leading data of the frame are dispersed to 320 positionsuniformly for each code. The sector ID is n dispersed for each byte.

[0206] In the ECC block shown in FIG. 25, the number of sub-sectors is320 and the leading data of the frame is dispersed at 320 positionsuniformly for each code. However, in an ECC block having the number ofsub-sectors equal to 160 and having a structure such that

[0207] number of sectors=16, number of frames=60, frame length=158 bytes

[0208] code length=237, interleave length=320

[0209] sector ID=20, k=1

[0210] segment length=1, p=20, number of sub-sectors=160,

[0211] the number of user data within the ECC block is 64 KB and thenumber of constituent sectors is 16. The leading data of the frame aredispersed to 160 positions at every two codes. Thus, the sector ID isdispersed for every byte.

[0212] Although the number of sectors is 16 in the ECC block shown inFIG. 25, the number of sectors can be changed.

[0213] For example, in an ECC block having the number of sectors equalto 32 and having a structure such that

[0214] number of sectors=32, number of frames=30, frame length=79 bytes

[0215] code length=237, interleave length=320

[0216] sector ID=10, k=1

[0217] segment length=1, p=10, number of sub-sectors=320,

[0218] the number of user data within the ECC block is 64 KB and thenumber of constituent sectors is 32. The leading data of the frame aredispersed to 320 positions uniformly for each code. Thus, the sector IDis dispersed for every byte.

[0219] Alternatively, in an ECC block having the number of sectors equalto 64 and having a structure such that

[0220] number of sectors=64, number of frames=15, frame length 79 bytes

[0221] code length=237, interleave length=320

[0222] sector ID=5, k=1

[0223] segment length=1, p=5, number of sub-sectors=320,

[0224] the number of user data within the ECC block is 64 KB and thenumber of constituent sectors is 64. The leading data of the frame aredispersed to 320 positions uniformly for each code. Thus, the sector IDis dispersed for every byte.

[0225] Moreover, in the ECC block shown in FIG. 25, the number of userdata within the ECC block is 64 KB. However, in an ECC block having astructure such that

[0226] number of sectors=16, number of frames=30, frame length=79 bytes

[0227] code length=237, interleave length=160

[0228] sector ID=10, k=1

[0229] segment length=1, p=10, number of sub-sectors=160,

[0230] the number of user data within the ECC block is 32 KB and thenumber of constituent sectors is 16. The leading data of the frame aredispersed to 160 positions uniformly for each code. Thus, the sector IDis dispersed for every byte.

[0231] Also, by using a disc format such that when the code length isdivisible by q (where q=number of subblocks: natural number), {{codelength/q}×interleave length}/{segment length×number of sub-sectors} %number of sub-sectors (where % indicates modulo) and the number ofsub-sectors are prime numbers, respectively, correction incapability dueto concentration of data of a specified position within the frame to aspecified code can be avoided.

[0232] Specifically, for example, an ECC block in which the code lengthobtained by binding and blocking codes of 208 information words and 30parity words for 320 lines is 238 (208 information words and 30 paritywords) and in which the interleave length is 320, as shown in FIG. 30A,is constituted by two subblocks as shown in FIG. 30B. The framestructure of the data of the ECC block is shown in FIG. 31A. As shown inFIG. 31A, the number of data of one frame is 119 bytes, and is modulatedto 1428 channels by (1, 7) modulation as shown in FIG. 31B.

[0233] In the frame structure shown in FIGS 31A and 31B, B(s, t, u, v)is modulated to m(s, t, u, w), where “s” represents the sector, “t”represents the frame, “u” represents the segment, “v” represents thedata (bytes), and “w” represents the channel after modulation. Inaddition, a DCC channel or the like for appending a DCC code to thecontrol of DC components in the (1, 7) modulation system by each DCcontrol cell (DCC) may be provided.

[0234] The configuration of recording/reproduction data on the disc isshown in FIG. 32. As shown in FIG. 32, a frame sync part FS is appendedto the header of a channel string on the frame (channel) basis. Also,APC and VFO parts are appended to the header of every 40 frames(channels) and a postamble PO is appended to the last part, thusconstituting one sector. In this case, APC is a light-emitting patternarea for controlling the recording laser power at the time of recording.VFO is a pattern area for applying PLL for clock extraction at the timeof reproduction. As the frame sync part FS, a unique pattern forrealizing channel synchronization, which does not appear in themodulation rule, is used. In this embodiment, as the frame sync FS, theframe sync FS0 indicating the header of the sector is discriminated fromthe other frame sync parts FS 1. However, a sector sync part SS may beinserted between VFO and FS.

[0235] In this ECC block, the following structure is employed.

[0236] number of sectors=16, number of frames=40, frame length 119 bytes

[0237] code length=238, interleave length=320

[0238] sector ID=20,k=2

[0239] segment length=1, p=20, number of sub-sectors=320

[0240] number of subblocks=2

[0241] Thus, in realizing correspondence of the data position on thedisc to the data position on the ECC block, the correction code positionis updated for each segment, that is, for each byte while the interleaverule is met. By doing so, the one-to-one correspondence between the dataon the disc and the data on the ECC block can be realized.

[0242] The frame structure within the ECC block is shown in FIG. 33.

[0243] In the ECC block shown in FIG. 30B, the direction of data on thedisc is provided by the rising order of B(s, t, u, v), that is, by thearrangement numbers from the upper position to the lower position in theorder of s, t, u and v. The relation between D(i, j) and B(s, t, u, v)is expressed by the following equation.

B(s, t, u, v)=D(i,j)=D([((((40×s)+t)×119+u)×1+v)/1 ]×2+[s/8]%238,((((40×s)+t)+t)×119+u)×1+v)%320)

[0244] If the block is not divided into subblocks, {codelength×interleave length}/{segment length×sub-sector length} % number ofsub-sectors=238 and the number of sub-sectors equal to 320 are not primenumbers with respect to each other. However, if the block is not dividedinto subblocks, {{code length/q (where q is the number of subblocks:natural number)}×interleave length}/[segment length×number ofsub-sectors} % number of sub-sectors=119 and the number of sub-sectorsequal to 320 are prime numbers with respect to each other. Bycontinuously arranging the sub-sectors on the disc, the one-to-onecorrespondence between the data of one block on the disc and the entiredata on the ECC block can be realized while the interleave rule is met.In this case, the header, that is, sector ID corresponds to the firsttwo words of information words of all the correction codes, and the userdata corresponds to the third and subsequent words of information wordsof all the correction codes. Therefore, the direction of user data canbe made equal to the direction of correction codes without beingdisturbed by the header.

[0245] The arrangement of data units within the ECC block and thestructure of data units are shown in FIG. 34. H(g, h) is headerinformation, that is, sector ID information. R(g, h) is 20-byteinformation at the leading part of each data unit. U(g, h) is user data.E(g, h) is an error detection code (EDC) of the user data. “g” is thenumber of data units, and “h” is the number of data.

[0246] The arrangement in which the direction of the user data U(g, h)is made equal to the direction of the error detection codes E(g, h) isexpressed by the following relational expressions between D(i, j) andR(g, h), U(g, h), E(g, h).

R(g, h)=D(i, j)=D((h%206)+2, 20×g+[h/206])=D(h+2, 20×g)

[0247] where h is 0 to 19 and g is 0 to 15

U(g, h)=D(i, j)=D(((20+h)%206)+2, 20×g+[(20+h)/206])

[0248] where h is 0 to 4095 and g is 0 to 15

E(g, h)=D(i, j)=D(((4116+h)%206)+2, 20×g+[(4116+h)/206])

[0249] where h is 0 to 3 and g is 0 to 15

[0250] As for the header information H(g, h), the following relationexpression is obtained.

H(g, h)=D(i, j)=D([g/8], (((40×g+h)/1)×119+((40×g+h)%1))%320)=D([g/8],((40×g+h)×119%320))

[0251] where h is 0 to 39 and g is 0 to 15

[0252] Thus, in the ECC block shown in FIG. 30B, the number of user datawithin the ECC block is 64 KB and the number of constituent sectors is16. The leading data of the frame are dispersed to 320 positionsuniformly for each code. The sector ID is dispersed for each byte.

[0253] As is clear from the above description, according to the presentinvention, data recording/reproduction is carried out in a format suchthat interleave processing is performed on error correction codes so asto collectively block the error correction codes into an errorcorrection unit and that the input/output order of user data in an ECCblock as an error correction unit is made coincident with the directionof processing of the error correction codes. Thus, coding can be startedat the time when necessary data for generating one code is transmitted,without waiting for transmission of data for one ECC block. Also,transmission of user data can be started at the time when correction ofone code is completed, without waiting for completion of correctionoperation for one ECC block. Therefore, the fixed delay at the time ofrecording/reproduction can be significantly reduced. Also, a margin canbe provided for data processing in reproduction and recording, or thebuffer memory can be reduced by reducing the total data processing time.In addition, since the direction of correction codes is the same as thedirection of user data, no memory for rearrangement of data is requiredand the hardware structure can be minimized. Moreover, since less datatransmission/reception takes place between the buffer memory and theexternal device, bus arbitration can be easily carried out.

[0254] Thus, the present invention can provide an optical discrecording/reproducing method, an optical disc and an optical disc devicefor recording/reproducing data in a disc format such that the fixeddelay at the time of recording/reproduction can be reduced.

[0255] Also, according to the present invention, datarecording/reproduction is carried out, for example, in a disc formatsuch that the ECC block is constituted by one or more sectors, thesector is constituted by a plurality of frames, the block length of theECC block is expressed by the following equation,

block length×number of sectors×number of frames×frame length=codelength×interleave length

[0256] the number of sub-sectors is expressed by the following equation,

number of sub-sectors=number of sectors×p

[0257] (where p=number of segments: natural number)

[0258] and {code length×interleave length}/{segment length×number ofsub-sectors} % number of sub-sectors (where % indicates modulo) and thenumber of sub-sectors are prime numbers, respectively. Thus, correctionincapability due to concentration of data of a specified position withina frame to a specified code can be avoided, and higher resistance toerrors generated by bit slip can be obtained.

[0259] Also, according to the present invention, datarecording/reproduction is carried out, for example, in a disc formatsuch that the ECC block is constituted by one or more sectors, thesector is constituted by a plurality of frames, the block length of theECC block is expressed by the following equation,

block length=number of sectors×number of frames×frame length=codelength×interleave length

[0260] the number of sub-sectors is expressed by the following equation,

number of sub-sectors=number of sectors×p

[0261] (where p=number of segments: natural number)

[0262] and when the code length is divisible by q (where q=number ofsubblocks: natural number), {{code length/q}×interleave length}/{segmentlength×number of sub-sectors} % number of sub-sectors (where % indicatesmodulo) and the number of sub-sectors are prime numbers, respectively.Thus, correction incapability due to concentration of data of aspecified position within a frame to a specified code can be avoided,and higher resistance to errors generated by bit slip can be obtained.

[0263] Moreover, according to the present invention, datarecording/reproduction is carried out, for example, in a disc formatsuch that the ECC block is constituted by one or more sectors, thesector is constituted by a plurality of frames, the block length of theECC block is expressed by the following equation,

block length×number of sectors×number of frames×frame length=codelength×interleave length

[0264] a sector ID is provided holding the following relations,

sector ID length×number of sectors=interleave length×k

[0265] (where k is a natural number)

sector ID length=segment length×p

[0266] (where p=number of segments: natural number) and {codelength×interleave length}/{segment length×number of sectors} % number ofsectors (where % indicates modulo) and the number of sectors are primenumbers, respectively. Thus, correction incapability due toconcentration of data of a specified position within a frame to aspecified code can be avoided, and higher resistance to errors generatedby bit slip can be obtained.

[0267] Thus, the present invention can provide an optical discrecording/reproducing method, an optical disc and an optical disc devicefor recording/reproducing data in a disc format such that correctionincapability due to concentration of data of a specified position withina frame to a specified code can be avoided.

1. An optical disc recording/reproducing method for carrying out datarecording/reproduction in a disc format such that error correction codesinterleaved with respect to the direction of data on a disc arecollectively blocked into an error correction unit and that theinput/output order of user data in an ECC block as an error correctionunit is made coincident with the direction of processing of the errorcorrection codes.
 2. The optical disc recording/reproducing method asclaimed in claim 1, wherein data recording/reproduction is carried outin a disc format such that the ECC block is constituted by one or moresectors, the sector is constituted by a plurality of frames, the blocklength of the ECC block is expressed by the following equation, blocklength×number of sectors×number of frames×frame length=codelength×interleave length the number of sub-sectors is expressed by thefollowing equation, number of sub-sectors=number of sectors×p (wherep=number of segments: natural number) and {code length×interleavelength}/{segment length×number of sub-sectors } % number of sub-sectors(where % indicates modulo) and the number of sub-sectors are primenumbers, respectively.
 3. The optical disc recording/reproducing methodas claimed in claim 2, wherein data recording/reproduction is carriedout in a plurality of disc formats having different ECC block sizes inaccordance with the setting of the number of sectors and interleavelength.
 4. The optical disc recording/reproducing method as claimed inclaim 2, wherein data recording/reproduction is carried out in a discformat such that the number of data within the segment is smaller thanthe number of data within the frame and that the correction codeposition is updated for each segment while the interleave rule is met incausing the data position on the disc to correspond to the data positionon the ECC block.
 5. The optical disc recording/reproducing method asclaimed in claim 4, wherein data recording/reproduction is carried outin a disc format such that the correction code position is updated byone byte.
 6. The optical disc recording/reproducing method as claimed inclaim 2, wherein data recording/reproduction is carried out in a discformat such that the ECC block is constituted by one or more sectors,the sector is constituted by a plurality of frames, the block length ofthe ECC block is expressed by the following equation, blocklength=number of sectors×number of frames×frame length=codelength×interleave length and a sector ID is provided holding thefollowing relation. sector ID length×number of sectors=interleavelength×k (where k is a natural number)
 7. The optical discrecording/reproducing method as claimed in claim 6, wherein datarecording/reproduction is carried out in a disc format such that thenumber of data within the segment is smaller than the number of datawithin the frame and that the correction code position is updated foreach segment on the basis of sector ID length as a unit while theinterleave rule is met in causing the data position on the disc tocorrespond to the data position on the ECC block.
 8. The optical discrecording/reproducing method as claimed in claim 6, wherein datarecording/reproduction is carried out in a plurality of disc formatshaving different ECC block sizes in accordance with the setting of thenumber of sectors and interleave length.
 9. The optical discrecording/reproducing method as claimed in claim 6, wherein discrecording/reproduction is carried out in a disc format such that thesector ID length is expressed by the following equation. sector IDlength=segment length×p (where p=number of segments: natural number) 10.The optical disc recording/reproducing method as claimed in claim 9,wherein data recording/reproduction is carried out in a disc format suchthat {code length×interleave length}/{segment length×number of sectors}% number of sectors (where % indicates modulo) and the number of sectorsare prime numbers, respectively.
 11. The optical discrecording/reproducing method as claimed in claim 10, wherein datarecording/reproduction is carried out in a disc format such that thenumber of sectors is 2^(n) and that {code length×interleavelength}/{sector ID length×number of sectors} is an odd number.
 12. Theoptical disc recording/reproducing method as claimed in claim 1, whereindata recording/reproduction is carried out in a disc format such thatthe ECC block is constituted by one or more sectors, the sector isconstituted by a plurality of frames, the block length of the ECC blockis expressed by the following equation, block length=number ofsectors×number of frames×frame length=code length×interleave length thenumber of sub-sectors is expressed by the following equation, number ofsub-sectors=number of sectors×p (where p=number of segments: naturalnumber) and when the code length is divisible by q (where q=number ofsubblocks: natural number), {{code length/q}×interleave length}/{segmentlength×number of sub-sectors } % number of sub-sectors (where %indicates modulo) and the number of sub-sectors are prime numbers,respectively.
 13. The optical disc recording/reproducing method asclaimed in claim 12, wherein data recording/reproduction is carried outin a plurality of disc formats having different ECC block sizes inaccordance with the setting of the number of sectors and interleavelength.
 14. The optical disc recording/reproducing method as claimed inclaim 12, wherein data recording/reproduction is carried out in a discformat such that the number of data within the segment is smaller thanthe number of data within the frame and that the correction codeposition is updated for each segment while the interleave rule is met incausing the data position on the disc to correspond to the data positionon the ECC block.
 15. The optical disc recording/reproducing method asclaimed in claim 14, wherein data recording/reproduction is carried outin a disc format such that the correction code position is updated byone byte.
 16. An optical disc having a disc format such that errorcorrection codes interleaved with respect to the direction of data on adisc are collectively blocked into an error correction unit and that theinput/output order of user data in an ECC block as an error correctionunit is made coincident with the direction of processing of the errorcorrection codes.
 17. The optical disc as claimed in claim 16, having adisc format such that the ECC block is constituted by one or moresectors, the sector is constituted by a plurality of frames, the blocklength of the ECC block is expressed by the following equation, blocklength=number of sectors×number of frames×frame length=codelength×interleave length the number of sub-sectors is expressed by thefollowing equation, number of sub-sectors=number of sectors×p (wherep=number of segments: natural number) and {code length×interleavelength}/{segment length×number of sub-sectors} % number of sub-sectors(where % indicates modulo) and the number of sub-sectors are primenumbers, respectively.
 18. The optical disc as claimed in claim 17,having a plurality of disc formats having different ECC block sizes inaccordance with the setting of the number of sectors and interleavelength.
 19. The optical disc as claimed in claim 17, having a discformat such that the number of data within the segment is smaller thanthe number of data within the frame and that the correction codeposition is updated for each segment while the interleave rule is met incausing the data position on the disc to correspond to the data positionon the ECC block.
 20. The optical disc as claimed in claim 19, having adisc format such that the correction code position is updated by onebyte.
 21. The optical disc as claimed in claim 17, having a disc formatsuch that the ECC block is constituted by one or more sectors, thesector is constituted by a plurality of frames, the block length of theECC block is expressed by the following equation, block length=number ofsectors×number of frames×frame length=code length×interleave length anda sector ID is provided holding the following relation. sector IDlength×number of sectors=interleave length×k (where k is a naturalnumber)
 22. The optical disc as claimed in claim 21, having a discformat such that the number of data within the segment is smaller thanthe number of data within the frame and that the correction codeposition is updated for each segment on the basis of sector ID length asa unit while the interleave rule is met in causing the data position onthe disc to correspond to the data position on the ECC block.
 23. Theoptical disc as claimed in claim 21, having a plurality of disc formatshaving different ECC block sizes in accordance with the setting of thenumber of sectors and interleave length.
 24. The optical disc as claimedin claim 21, having a disc format such that the sector ID length isexpressed by the following equation. sector ID length×segment length×p(where p number of segments: natural number)
 25. The optical disc asclaimed in claim 24, having a disc format such that {codelength×interleave length}/{segment length×number of sectors} % number ofsectors (where % indicates modulo) and the number of sectors are primenumbers, respectively.
 26. The optical disc as claimed in claim 25,having a disc format such that the number of sectors is 2^(n) and that{code length×interleave length}/{sector ID length ×number of sectors} isan odd number.
 27. The optical disc as claimed in claim 16, having adisc format such that the ECC block is constituted by one or moresectors, the sector is constituted by a plurality of frames, the blocklength of the ECC block is expressed by the following equation, blocklength=number of sectors×number of frames×frame length=codelength×interleave length the number of sub-sectors is expressed by thefollowing equation, number of sub-sectors=number of sectors×p (wherep=number of segments: natural number) and when the code length isdivisible by q (where q=number of subblocks: natural number), {{codelength/q}×interleave length}/{segment length×number of sub-sectors} %number of sub-sectors (where % indicates modulo) and the number ofsub-sectors are prime numbers, respectively.
 28. The optical disc asclaimed in claim 27, having a plurality of disc formats having differentECC block sizes in accordance with the setting of the number of sectorsand interleave length.
 29. The optical disc as claimed in claim 27,having a disc format such that the number of data within the segment issmaller than the number of data within the frame and that the correctioncode position is updated for each segment while the interleave rule ismet in causing the data position on the disc to correspond to the dataposition on the ECC block.
 30. The optical disc as claimed in claim 29,having a disc format such that the correction code position is updatedby one byte.
 31. An optical disc device comprising recording/reproducingmeans for carrying out data recording/reproduction in a disc format suchthat error correction codes interleaved with respect to the direction ofdata on a disc are collectively blocked into an error correction unitand that the input/output order of user data in an ECC block as an errorcorrection unit is made coincident with the direction of processing ofthe error correction codes.
 32. The optical disc device as claimed inclaim 31, wherein the recording/reproducing means carries out datarecording/reproduction in a disc format such that the ECC block isconstituted by one or more sectors, the sector is constituted by aplurality of frames, the block length of the ECC block is expressed bythe following equation, block length=number of sectors×number offrames×frame length=code length×interleave length the number ofsub-sectors is expressed by the following equation, number ofsub-sectors=number of sectors×p (where p=number of segments: naturalnumber) and {code length×interleave length}/{segment length×number ofsub-sectors } % number of sub-sectors (where % indicates modulo) and thenumber of sub-sectors are prime numbers, respectively.
 33. The opticaldisc device as claimed in claim 32, wherein the recording/reproducingmeans carries out data recording/reproduction in a plurality of discformats having different ECC block sizes in accordance with the settingof the number of sectors and interleave length.
 34. The optical discdevice as claimed in claim 32, wherein the recording/reproducing meanscarries out data recording/reproduction in a disc format such that thenumber of data within the segment is smaller than the number of datawithin the frame and that the correction code position is updated foreach segment while the interleave rule is met in causing the dataposition on the disc to correspond to the data position on the ECCblock.
 35. The optical disc device as claimed in claim 34, wherein therecording/reproducing means carries out data recording/reproduction in adisc format such that the correction code position is updated by onebyte.
 36. The optical disc device as claimed in claim 32, wherein therecording/reproducing means carries out data recording/reproduction in adisc format such that the ECC block is constituted by one or moresectors, the sector is constituted by a plurality of frames, the blocklength of the ECC block is expressed by the following equation, blocklength=number of sectors×number of frames×frame length=codelength×interleave length and a sector ID is provided holding thefollowing relation. sector ID length×number of sectors=interleavelength×k (where k is a natural number)
 37. The optical disc device asclaimed in claim 36, wherein the recording/reproducing means carries outdata recording/reproduction in a disc format such that the number ofdata within the segment is smaller than the number of data within theframe and that the correction code position is updated for each segmenton the basis of sector ID length as a unit while the interleave rule ismet in causing the data position on the disc to correspond to the dataposition on the ECC block.
 38. The optical disc device as claimed inclaim 36, wherein the recording/reproducing means carries out datarecording/reproduction in a plurality of disc formats having differentECC block sizes in accordance with the setting of the number of sectorsand interleave length.
 39. The optical disc device as claimed in claim36, wherein the recording/reproducing means carries out discrecording/reproduction in a disc format such that the sector ID lengthis expressed by the following equation. sector ID length segmentlength×p (where p number of segments: natural number)
 40. The opticaldisc device as claimed in claim 39, wherein the recording/reproducingmeans carries out data recording/reproduction in a disc format such that{code length×interleave length}/{segment length×number of sectors} %number of sectors (where % indicates modulo) and the number of sectorsare prime numbers, respectively.
 41. The optical disc device as claimedin claim 40, wherein the recording/reproducing means carries out datarecording/reproduction in a disc format such that the number of sectorsis 2^(n) and that {code length×interleave length}/{sector IDlength×number of sectors} is an odd number.
 42. The optical disc deviceas claimed in claim 31, wherein the recording/reproducing means carriesout data recording/reproduction in a disc form at such that the ECCblock is constituted by one or more sectors, the sector is constitutedby a plurality of frames, the block length of the ECC block is expressedby the following equation, block length=number of sectors×number offrames×frame length=code length×interleave length the number ofsub-sectors is expressed by the following equation, number ofsub-sectors=number of sectors×p (where p=number of segments: naturalnumber) and when the code length is divisible by q (where q=number ofsubblocks: natural number), {{code length/q}×interleave length}/{segmentlength×number of sub-sectors} % number of sub-sectors (where % indicatesmodulo) and the number of sub-sectors are prime numbers, respectively.43. The optical disc device as claimed in claim 42, wherein therecording/reproducing means carries out data recording/reproduction in aplurality of disc formats having different ECC block sizes in accordancewith the setting of the number of sectors and interleave length.
 44. Theoptical disc device as claimed in claim 42, wherein therecording/reproducing means carries out data recording/reproduction in adisc format such that the number of data within the segment is smallerthan the number of data within the frame and that the correction codeposition is updated for each segment while the interleave rule is met incausing the data position on the disc to correspond to the data positionon the ECC block.
 45. The optical disc device as claimed in claim 44,wherein the recording/reproducing means carries out datarecording/reproduction in a disc format such that the correction codeposition is updated by one byte.